Grzegorz =?iso-8859-2?q?Prze=BCdziecki?= <Grzegorz.Przezdziecki@PolskieSklepy.pl> writes:
>> It won't work and will likely crash the backend.
> Even if I will do like this and for ever??
> 1. attnum will be unique and greater than 0
> 2. no holes in attnum numeric
> 3. Make change
> 4. restart postgresql
Yes, unless you also TRUNCATE the table, because attnum ordering tells
about the physical data layout within the table rows. Furthermore,
altering only pg_attribute is unlikely to represent a complete update
of the catalogs --- attnums also show up in pg_index, pg_attrdef,
pg_depend, pg_rewrite if there are any rules or views mentioning the
columns, and probably some other places I forgot.
regards, tom lane